I'd recommend buying the parts you need from either DangerDen or D-Tek. You should buy an Eheim 1048 from
http://seame.com/ as you're a Swede like me
The 1048 only costs "485 kr inkl moms + frakt" from them which is a bargain, of course you have to pay with VISA or Mastercard but that's the easy part.
A DD system would consist of a Maze-3 and a Heater Core and you'd have to build yourself a shroud for the core but that's no biggie.
If you choose D-Tek they carry the amazing Gemini block which outperforms some other popular blocks:
http://www.overclockers.com/articles546/
I'd guess it's equal to or slightly better than the Maze-3.
D-Tek also carries some excellent heater cores with shrouds to save you some work.
The shipping from D-Tek is a little high, 60$ for USPS is not cheap.. DD would charge you $25 so it should be accounted for when you make your decision.
Additionally, purchase some water wetter to prevent corrosion and improve cooling efficiency, and go with silicon or tygon tubing and 1/2" on all parts.. that is 9 mm ID. 3/8" is only 7 mm ID.